The present invention relates to the field of construction of fluid ejection devices such as inkjet printheads and, in particular, discloses the utilization of an ancillary ink flow prevention formation on the surface of the printhead.
Recently, the present applicant has proposed, for example, in PCT Application No. PCT/AU98/00550 the utilization of inkjet printheads having a large array of ink ejection nozzles on the surface of a wafer. Unfortunately, most inkjet printing devices utilize a large array of ink ejection nozzles from which to eject fluid on demand from the nozzles.
The utilization of a fluid system having a series of nozzles exposed to an ambient atmosphere can give rise to problems due to xe2x80x9cwickingxe2x80x9d of fluids along surfaces. The wicking can often be aided by foreign debris or foreign bodies in the ink or atmosphere adjacent the nozzles. This is especially the case where printing of the paper is utilized where paper dust and other debris can effect the inkjet printers. This wicking can result in malfunction of the device due to the loss of control of the ink on the surface adjacent the ink ejection nozzles.
It is an object of the present invention to provide an ink flow prevention rims about each of a series of ink ejection nozzles so as to limit or reduce the potential flow of ink across a surface of an ink jet printhead.
In accordance with a first aspect of the present invention, there is provided an inkjet printhead having a series of ink ejection nozzles for the ejection of ink, each of said nozzles interconnecting a nozzle chamber with an external atmosphere, each said nozzle having a first meniscus rim around which an ink meniscus normally forms, and an extended ink flow prevention rim spaced outwardly from said first meniscus rim and substantially encircling said first meniscus rim, arranged to prevent the flow of ink across the surface of said inkjet printhead.
The ink flow prevention rim can be substantially co-planar with the first meniscus rim and can be formed from the same material as the first meniscus rim.
The ink flow prevention rim and the first meniscus rim are preferably formed utilizing chemical mechanical planarization.
The ink flow prevention rim and the first meniscus rim are preferably formed from Titanium Nitride.